Tyrian Purple

Colored textiles date back to very ancient times. One particularly interesting era is that of Tyrian purple. In the Bronze Age, the Phoenicians became famous for their coveted purple dye (including the production techniques). The purple color was extracted from murex shellfish, and it reportedly took around 10,000 shellfish to yield only a gram of dye! Mounds of shells have been found in or near the ancient cities Tyre, Sidon, and others. The beautiful, deep purple was therefore very costly and reserved only for royalty or the very rich. The Phoenicians had perfected their processes so that Tyrian purple was known for resisting fading and outdid the "cheaper" purples on many levels.
Check out the Ancient History article link included for more amazing details on the history of purple.